The present invention relates to a method of circulating ground water in ground regions with a fall of ground water level.
It is known to form withdrawal and absorption wells in ground regions through which ground water flows, for subsequently pumping out ground water from the withdrawal wells and then further advance the absorption wells. Thereby a drawing-in region is produced in the surrounding area of the withdrawal well, from which the ground water flows into the well. This can be recognized by lowering the ground water level into the surrounding area of the withdrawal well. On the other hand, a ground water expelling region with a raised ground water level is formed in the surrounding area of the absorption well, so that an desired circulation of the ground water through the ground region is provided. Because of this circulation, the ground water can be cleaned from contamination and/or prepared for producing drinking water.
The known methods have the advantage that, for pumping out of the ground water from the withdrawal well up to the ground surface a high energy consumption is required. Moreover, the ground water during pumping is subjected to warming up due to the density change. This leads to the problems of resupplying of the water into the absorption well. The warm water layer remains on the surface of the ground water-guiding layer, so that only a small mixing and circulation of the ground water and therefore a low efficiency during cleaning of the ground water is obtained. Moreover, the pumping out of the ground water leads to a change of the isobar and isotherm in the ground water, so that during a phase saturation for example with iron or lime always crystalline deposits and thereby clogging of wells and ground occur.